Double mast antenna having the upper mast supported by a carrier mast which extends the length of the lower mast



Feb. 7, 1967 H. DIEBOLD 3,303,506

DOUBLE MAST ANTENNA HAVING THE UPPER MAST SUPPORTED BY A CARRIER MASTWHICH EXTENDS THE LENGTH OF THE LOWER MAST Filed June 11, 1963 UnitedStates Patent 7 Claims. 61. s4s-s72 The invention disclosed herein isconcerned with an antenna mast of great height, made of tubular sectionsof insulating material, for antennas operating in the ultra short waverange or decimeter wave range.

The construction of a transmitter antenna with an array of directionalantennas, for example, omnidirectional antennas operating in the ultrashort wave range or in the decimeter wave range, is limited by themechanical stability of the supporting elements of the array. Thisbecomes particularly apparent when it is attempted to arrange upon amast, tower or other carrier, in superposed relationship, a plurality ofantennas for operation in the same or in different frequency ranges.

The invention relates to an antenna mast comprising tubular envelopesmade of insulating material, assembled to form the facing or themounting means for a plurality of antennas operating in the ultra shortwave range or in the decimeter wave range, especially for televisionantennas, omindirectional antennas and the like.

The principal object of the invention is to provide antenna masts ofthis kind, which are of great structural height and have sufiicientmechanical stability, employing tubular sections made of insulatingmaterial.

In a known arrangement which attemps to solve the problems involved, theantenna elements are fastened to a carrier mast, and the whole structureis surrounded by a protective electrically permeable tubular envelopewhich is likewise mechanically directly fastened to the carrier mast.The distadvantage resides in the great weight which such an arrangementassumes when constructed so as to withstand the wind pressures that maybe expected to act thereon. Moreover, entering into and climbing withinthe protective envelope are made practically impossible.

Another solution for the pertinent problems involved in connection witha sender antenna comprising dipoles, is described in the Germanauslegeschrift 1,078,643. The arrangement provides a tubular mast madeof insulating material, serving as a carrier for the dipoles which arefastened to the inside wall thereof, and surround them as a protectionagainst atmospheric influences. The dipoles are constructed as rigidunits mounted with the aid of struts in a polygon arrangement on theinner wall of the self-supporting tubular envelope forming the mast, sothat the tubular envelope, which is made of insulating material, servesas the sole carrier for the entire antenna arrangement. Accordingly, theprotective tubular envelope forms the carrier element. The structuralheight is limited by the maximum permissible wall thickness of theelements forming the tubular envelope.

It has also been proposed to reinforce the known selfsupporting tubularmast, made of insulating material, with the aid of auxiliary steelcarriers within the respective dipole groups or by stiffening insertsdisposed in the wall of the tubular envelope. Difficulties arise inconnection with such structures due to the fact that the corres ondingsystems cannot be easily comprehended statically.

According to the invention, the above indicated drawbacks are overcomeby arranging in superposed coaxial relation two separate self-supportingtubular mast portions or envelopes comprising tubular sections made ofinsulating material, and supporting the upper mast envelope upon acarrier mast which extends freely upwardly from the foundation of thelower mast portion, inside of the latter, without any direct mechanicalconnection with the tubular insulating sections of the lower mastenvelope.

The structure according to the invention results in definite staticconditions since the protective envelope or tubular structure of thelower antenna portion assumes the entire wind pressure acting thereon.The carrier mast for supporting the upper antenna envelope is thuscompletely free of wind pressure. The tubular antenna mast comprisingtubular sections made of insulating material, can in this manner beconstructed with considerably greater height, without entailingdifficulties.

Details of the invention will appear from the appended claims and fromthe description of an embodiment which is rendered below with referenceto the accompanying drawing.

The drawing shows an embodiment of an antenna mast made of tubularinsulating material, comprising an upper envelope which is indicated inelevation and a lower envelope which is represented in sectional view.

Referring now to the drawing, numeral 1 indicates a foundation which isdisposed, for example, on top of a tower or upon an antenna mast ofgreater diameter. Upon this foundation is built a self-supporting lowermast envelope comprising, for example, eight tubular sections 2 made ofinsulating material. A carrier mast 3 which is by suitable and knownmeans held on the foundation 1 extends freely upwardly therefrom,through the interior of the tubular lower envelope made of insulatingmaterial, and carries an upper envelope made of insulating materialconstructed similarly of tubular insulating material sections 2. Thecarrier mast 3 for supporting the upper mast envelope is constructed asa polygonal, for example, as -a four-sided metal grid mast withconsiderably smaller cross-section than the tubular insulating sectionsof the corresponding envelope. There are no direct mechanicalconnections between the inner carrier mast 3 and the tubular insulatingmaterial sections 2 of the lower envelope of the mast.

At the upper end of the carrier mast 3 is provided a plateor disk-likesupport 4 with a diameter corresponding approximately to that of thetubular insulating material sections, upon which is supported thetubular upper envelope of the mast. Numeral 5 indicates a flexibleweather-resistant facing.

The antennas 6 in the lower mast envelope, which are, for example,constructed as dipoles, may be fastened, as shown, on the carrier mast3, or may be fastened in known manner, by means of struts, on the innerwalls of the respective tubular sections 2 of insulating material, asillustrated in German auslegeschrift 1,078,643. The antennas 6 in theupper mast envelope, which does not contain an interior carrier mast,are suitably held by' struts 12 on the inner walls of the respectivetubular envelope sections 2. Numeral 7 indicates a top cover andnumerals 8 indicate lamps for illuminating it.

The lowermost tubular section 2 of the lower mast envelope is held upona suitable support 9 of the foundation -1. Numerals 10 indicate meansfor holding the carrier mast 3.

The tubular sections 2 and 2' are made, for example, of synthetic glassfiber material or of fiber glass material. Reinforcing rings or flanges11 are provided at the ends of the tubular sections for the assemblythereof with adjacent sections.

There is in this manner provided an antenna structure comprising twoseparate tubular self-supporting insulating material mast envelopeswhich can move or sway independently responsive to wind pressure actingthereon. Antennas for identical or for different ranges, for example,television bands, can be provided in the respective lower and upper mastenvelopes. The respective mast envelopes may be provided with separateantennas or may contain interconnected parts forming a common array.

Changes may be made within the scope and spirit of the appended claimswhich define what is believed to be new and desired to have protected byLetters Patent.

I claim:

1. An antenna mast for a plurality of antennas operating in the ultrashort wave range or in the decimeter wave range, especially fortelevision antennas, omnidirectional antennas and the like, comprisingtwo separate individually self-supporting tubular envelopes arranged insuperposed relationship, each envelope comprising a plurality of tubularsections made of insulating material, means forming a foundation onwhich the lower antenna envelope is supported, and a carrier mastsupported by said foundation and extending freely upwardly therefromwithin said lower envelope, on which the upper antenna envelope issupported.

2. An antenna mast according to claim 1, wherein said carrier mast isconstructed as a polygonal metal grid mast with a cross-section smallerthan that of the tubular envelope sections.

3. An antenna mast according to claim 2, comprising a plate-like membercarried by said carrier mast at the upper end thereof for supportingsaid upper antenna envelope.

4. An antenna mast according to claim 3, comprising flexible meansconnecting the lower end of the upper tubular antenna envelope with theupper end of the lower tubular envelope.

5. An antenna mast according to claim 3, comprising flexibleweather-resistant means enclosing the space between the lower end of theupper tubular antenna envelope and the upper end of the lower tubularantenna envelope.

6. An antenna mast comprising means forming a foundation, a carrier mastconstructed as a polygonal metal grid mast secured to and upwardlyextending from said foundation, a first tubular envelope likewisesecured to and extending upwardly from said foundation, said firstenvelope comprising a plurality of superposed tubular sections made ofinsulating material surrounding said carrier mast radially spacedtherefrom without any direct mechanical connection therewith, aplate-like support carried by said carrier mast at the top thereof, asecond tubular envelope supported by and extending upwardly from saidplate-like support, said second envelope likewise comprising a pluralityof superposed tubular sections made of insulating material, antennasenclosed by said first and second tubular envelopes, and a flexibleweather-resistant facing enclosing the space between the lower end ofsaid second tubular envelope and the upper end of the first tubularenvelope.

7. An antenna mast comprising two superposed coaxially verticallyextending tubular envelopes, each envelope enclosing antennas, eachenvelope comprising a plurality of superposed tubular sections made ofinsulating material, means forming a foundation for directly supportingthe lower one of said tubular envelopes, and supporting means forindependently supporting on said foundation the upper one of saidenvelopes, said supporting means comprising a carrier mast made in theform of a polygonal metal grid mast fastened to said foundation andextending vertically freely upwardly therefrom interiorly of said lowertubular envelope without any direct mechanical connection therewith, anda plate-like support carried by said carrier mast at the upper endthereof for supporting said tubular upper envelope.

References Cited by the Examiner UNITED STATES PATENTS 2,441,086 5/1948Stinson 343827 X 2,532,551 12/1950 Jarvis 343872 X 2,760,191 8/1956Blackmer et al. 343872 X 2,771,606 11/1956 Kandoian 343890 3,153,23910/1964 Adams 343872 X FOREIGN PATENTS 1,078,643 3/ 1960 Germany.

HERMAN KARL SAALBACH, Primary Examiner.

P. L. GENSLER, Assistant Examiner.

1. AN ANTENNA MAST FOR A PLURALITY OF ANTENNAS OPERATING IN THE ULTRASHORT WAVE RANGE OR IN THE DECIMETER WAVE RANGE, ESPECIALLY FORTELEVISION ANTENNAS, OMNIDIRECTIONAL ANTENNAS AND THE LIKE, COMPRISINGTWO SEPARATE INDIVIDUALLY SELF-SUPPORTING TUBULAR ENVELOPES ARRANGED INSUPERPOSED RELATIONSHIP, EACH ENVELOPE COMPRISING A PLURALITY OF TUBULARSECTIONS MADE OF INSULATING MATERIAL, MEANS FORMING A FOUNDATION ONWHICH THE LOWER ANTENNA ENVELOPE IS SUPPORTED, AND A CARRIER MASTSUPPORTED BY SAID FOUNDATION AND EXTENDING FREELY UPWARDLY THEREFROMWITHIN SAID LOWER ENVELOPE, ON WHICH THE UPPER ANTENNA ENVELOPE ISSUPPORTED.